commands: clearly define how arguments are counted in request error

src/commands.rs

@@ -60,7 +60,11 @@ where
     /// The minimum number of arguments this command takes
     const MIN_ARGS: u32;
 
-    /// The maximum number of arguments this command takes
+    /// The maximum number of arguments this command takes.
+    ///
+    /// Note that in the case of keyworded arguments, such as
+    /// `group <groupname>`, `sort <sorting>`, etc., these are
+    /// counted as a single argument despite being two tokens.
     const MAX_ARGS: Option<u32>;
 
     /// Helper function to create a [`RequestParserError::TooManyArguments`] error
@@ -555,6 +559,10 @@ pub enum RequestParserError {
     )]
     SubtypeParserError {
         /// The index of the argument that failed to parse
+        ///
+        /// Note that in the case of keyworded arguments, such as
+        /// `group <groupname>`, `sort <sorting>`, etc., these are
+        /// counted as a single argument despite being two tokens.
         argument_index: u32,
 
         /// The expected type of the argument
@@ -577,6 +585,10 @@ pub enum RequestParserError {
         expected_max: Option<u32>,
 
         /// The number of arguments that were found
+        ///
+        /// Note that in the case of keyworded arguments, such as
+        /// `group <groupname>`, `sort <sorting>`, etc., these are
+        /// counted as a single argument despite being two tokens.
         found: u32,
     },
 
@@ -593,6 +605,10 @@ pub enum RequestParserError {
         expected_max: Option<u32>,
 
         /// The number of arguments that were found
+        ///
+        /// Note that in the case of keyworded arguments, such as
+        /// `group <groupname>`, `sort <sorting>`, etc., these are
+        /// counted as a single argument despite being two tokens.
         found: u32,
     },